The present invention relates to sliding-caliper disk-brakes provided with a wedge type operating mechanism. Brakes of this kind are generally used in motor vehicles of the truck type and are well known to those skilled in the art.
U.S. Pat. No. 4,621,713 describes one example of a brake- of this kind. A piston is coupled to a brake pad and the caliper to another pad. Convergent inclined surfaces of a wedge cooperating with rollers between the surfaces of the piston and caliper enable these surfaces to be moved apart relative to one another by longitudinal displacement of the wedge, thus bringing the brake pads and the disk into contact. The force applied to the wedge is therefore converted into two opposite forces at right angles to the plane of the disk. This force applied to the wedge is generated by a diaphragm vessel fixed to the caliper and generally operated by compressed air. The reaction force is therefore applied directly to the means fastening the vessel to the caliper.
The caliper slides, likewise in known manner, relative to the clevis on at least one column fixed to the clevis. This column receives a substantial part of the brake force. During braking, in fact, the friction between the pad driven by the caliper and the disk produces a force parallel to the disk and directed in the direction of rotation of the disk. This force is at right angles to the axis of the column and tends to turn the caliper about the zone of contact between the caliper and the column. This results in the flection of the latter, which must then be oversized, and in a less easy sliding of the caliper on the column in proportion to the brake force increase.